Why California’s most productive salmon hatchery is millions of fish short

Chinook salmon released into Battle Creek

Nearly 300,000 late-fall Chinook are released into Battle Creek in Northern California on December 21, 2017. These are the offspring of fish spawned last year during January and February. Battle Creek runs 16.6 miles in Shasta and Tehama counties.

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Nearly 300,000 late-fall Chinook are released into Battle Creek in Northern California on December 21, 2017. These are the offspring of fish spawned last year during January and February. Battle Creek runs 16.6 miles in Shasta and Tehama counties.

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California’s most productive salmon hatchery has 6 million fewer fish this year, another sign the state’s drought woes linger despite last winter’s record rainfall.

The federal Coleman National Fish Hatchery tries to produce about 12 million fall-run Chinook salmon for release each spring into Battle Creek, a Sacramento River tributary south of Redding. This spring, the Coleman hatchery will only have half as many young salmon to release.

The reason harkens back to the abysmal river conditions in the heart of California’s historic five-year drought – and the choices fishery managers made those years to move the baby Chinook by tanker truck out to sea in a frantic effort to save the commercially important fish.

They knew at the time trucking the fish would lead to fewer fish coming back to Coleman this year to spawn.

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“Everybody kind of acknowledged and understood at the time the consequences,” said John McManus, executive director of the Golden Gate Salmon Association, a fishing advocacy group.

Chinook live two or three years in the Pacific Ocean before adult fish head back upriver to lay their eggs and die, starting the cycle anew. Fish hatched in California’s five-year drought that ended officially in the spring are returning to Central Valley rivers this year.

Almost all of the Central Valley’s fall-run Chinook are hatched from eggs and sperm that biologists harvest from adults that return to hatcheries below the dams blocking the fish from their traditional spawning habitat.

Fall-run adult fish – raised at five hatcheries across the Central Valley – provide the bulk of the fish caught in the commercial and recreational fishing industry. McManus and other fishing advocates say fall-run Chinook support $1.4 billion in annual economic activity in California and about 23,000 fishing related jobs while providing locally caught fish for Californians’ dinner tables.

Because of the hatcheries, fall-run Chinook (and the smaller late fall-run) are the only Central Valley salmon runs healthy enough to avoid protections under the U.S. Endangered Species Act. The spring run is listed as threatened. The winter-run is critically endangered. The runs are named for the season when the majority of the adult fish enter freshwater.

The drought played havoc on all the runs, which need cold water to thrive. Returns of spring- and winter-run Chinook born during the drought are among the lowest on record.

The dry winters of 2014 and 2015 left the Central Valley’s rivers languid, clear and warm for long stretches – terrible conditions for a young salmon, and particularly perilous for fish that hatch far upriver because they have farther to swim.

Salmon are a cold-water fish, and juveniles are more likely to survive their trip to the sea when they have plenty of food and can avoid predators in rivers cloudy and swift from nutrient-rich stormwater runoff.

Coleman is the farthest Sacramento Valley hatchery from the Pacific. Young fish – called smolts – hatched at Coleman have to swim 280 miles of river to reach salt water. Normally, that journey helps them navigate back to their hatchery years later.

In the dry spring of 2014, Coleman’s managers decided that the Sacramento River was so warm that almost all Coleman fish would die if they were released into Battle Creek – a move that would potentially kill the salmon fishing industry a couple of years later when the fish grew into adults.

So that spring, all 12 million Coleman fish were sucked into dozens of tanker trucks, driven to the Sacramento-San Joaquin Delta and dumped into floating pens near Rio Vista to acclimate them for later release.

Coleman fish weren’t the only fish trucked. Millions more juvenile fall-run fish raised at the Central Valley’s four other salmon hatcheries were also transported.

The process repeated the following year.

The trucking program likely saved this year’s fishing season.

Biologists estimated this spring there were 230,700 in the Pacific Ocean waiting to pass under the Golden Gate Bridge and head upriver into the Central Valley. Though 70,000 fewer than last year, there were enough adult fish to allow for a commercial fishing season off a portion of California’s coast. Recreational anglers also had some fish to catch this summer and fall in the Sacramento River and in its tributaries, the Feather and the American rivers.

By comparison, this year’s salmon fishing season was closed on the Klamath River. No salmon are trucked from that river’s hatchery below Iron Gate Reservoir.

Enough adult fish also returned to the four other Central Valley hatcheries for those facilities to reach their egg and smolt production goals.

It’s another story at Coleman, where only a small fraction of the adults made it back. Biologists said the trucking process badly disoriented almost all of the young fish when they returned as adults.

As many as 143,000 adult fish will return to the Coleman hatchery to spawn in a normal year. In 2017, only around 3,000 adults returned, enough to fertilize about 4 million eggs – well shy of the hatchery’s 12 million goal.

Many of the wayward adult fish hatched at Coleman actually ended up at the state’s Nimbus Hatchery on the American River in Rancho Cordova. Biologists know they were Coleman fish because they insert specially coded wire tags the size of a pencil tip into a percentage of hatchery smolts.

This fall, state and federal biologists were able to gather an additional 2 million fertilized eggs at Nimbus from the Coleman fish that got lost and ended up there. Those eggs were transported to Coleman.

The question is whether having just 6 million fish at Coleman will translate into worse fishing seasons in the years ahead.

Stone said he and his fellow fishing guides are frustrated that more fertilized eggs weren’t taken from other hatcheries to offset Coleman’s low numbers.

Biologists chose not to go that route because they’re wary of intermingling the the genetic strains of the fish that spawn in the various rivers, said Shane Hunt, a spokesman for the U.S. Fish and Wildlife Service, which manages Coleman.

“A multitude of variables affects adult salmon returns, including ocean and river conditions several months or even years from now,” Clifford said in an email. “Some year(s) classes of salmon do better than others.”

In other words, the best hope for the fish – and the anglers who hope to catch them someday – is that this dry December doesn’t translate into another prolonged drought.